GHSA-c8r8-95hg-mp34
SiYuan: MCP file tool's blocklist is incomplete relative to the HTTP file API it claims to align with, exposing publish-mode passwords and other sensitive workspace files
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| Go | github.com/siyuan-note/siyuan/kernel | < 0.0.0-20260808051406-3542530c505f | 0.0.0-20260808051406-3542530c505f |
Details
As written in the advisory (Markdown source, shown as plain text).
## Summary
`kernel/mcp/tools/file.go`'s `resolvePath()` includes an explicit comment stating its
sensitive-path blocklist is meant to align with the HTTP file API's established blacklist
(`refuseToAccess()` in `kernel/api/file.go`), following the remediation for GHSA-cvhv-7xhj-xjp8
("Unauthenticated Administrator takeover exfiltrated via the MCP"), which specifically
recommended restricting this tool's scope. In practice, the MCP tool implements only 1 of the
4 static blocklist entries the HTTP API enforces.
## Comparison
`kernel/api/file.go` `refuseToAccess()` blocks:
1. `conf/conf.json` (API token, cookie signing key, accessAuthCode)
2. `data/snippets/conf.json`
3. the entire `data/templates` directory
4. `data/.siyuan/publishAccess.json`
5. (dynamic, per-request) any path the current publish-mode session isn't authorized for
`kernel/mcp/tools/file.go` `resolvePath()` blocks only:
```go
confPath := filepath.Join(util.ConfDir, "conf.json")
if abs == confPath {
return "", fmt.Errorf("access to conf.json is forbidden")
}
```
Items 2, 3, and 4 are absent. The tool's own `list`/`read`/`grep`/`find` actions remain fully
functional against them.
## Impact
An MCP client with access to the `file` tool (post-fix for GHSA-cvhv-7xhj-xjp8, i.e. a properly
authenticated Administrator-level caller) can read `data/.siyuan/publishAccess.json` directly:
```go
type PublishAccessItem struct {
ID string `json:"id"`
Visible bool `json:"visible"`
Password string `json:"password"` // plaintext; empty string = no password
Disable bool `json:"disable"`
}
```
This exposes the plaintext access password for every publish-mode-shared notebook/document,
letting the reader bypass password protection on any publish-mode share. This is a serious
sibling issue given the volume of publish-mode access-control bugs already reported against this
codebase — the passwords protecting exactly that feature are directly readable through a tool
whose own description says "never use for workspace data."
`data/templates` and `data/snippets/conf.json` are lower-severity but still inconsistent with
the HTTP API's own precedent for what counts as sensitive.
## Why this is a distinct finding, not a duplicate
GHSA-cvhv-7xhj-xjp8 was about *reachability* an unauthenticated Reader-tier JWT being forwarded
to admin-scoped paths including `/mcp`. That has been fixed. This report is about the *tool's own
scope* once reached by a legitimate, properly-authenticated caller, the remediation notes for
that same advisory explicitly called for restricting `resolvePath` to
`WorkspaceDir/temp/siyuan/*.log`, which was not implemented; instead the tool retains
workspace-wide scope with only a single-file blocklist addition.
## Suggested fix
Either replicate the full `refuseToAccess()` blocklist in `resolvePath()` (minimum fix, keeps
parity with the HTTP API going forward by extracting `refuseToAccess`'s path list into a shared
helper both call), or implement the originally-recommended allowlist restricting the tool to
`WorkspaceDir/temp/siyuan/*.log` for read and disabling write/delete/rename/copy entirely unless
the caller is Administrator, matching the tool's own advertised "debugging/log reading only"
scope.
References
External links from the advisory. They lead to third-party sites.
- https://github.com/siyuan-note/siyuan/security/advisories/GHSA-c8r8-95hg-mp34
- https://nvd.nist.gov/vuln/detail/CVE-2026-60083
- https://github.com/siyuan-note/siyuan/commit/3542530c505f13aa3fbd0343627409ca6c000dd2
- https://github.com/siyuan-note/siyuan
- https://github.com/siyuan-note/siyuan/releases/tag/v3.8.0
- https://www.vulncheck.com/advisories/siyuan-before-incomplete-path-blocklist-via-mcp-file-tool